Boiler feed apparatus



Dec. '21, 1237.

V. E. M COY ET AL BOILER FEED APPARATUS 2 Sheets-Sheet l I Filed June 6,1935 fmjezzfanz UeFZ/EMC C0 J, wider-@072,

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1937. v. E. M COY ET AL BOILER FEED APPARATUS Filed June 6, 1935 2Sheets-Sheet 2 [XerLE'Mc @y, I

WM MMMQLM Qpy Patented Dec. 21, 1937 UNITED STATES PATENT OFFICE.

BOILER FEED APPARATUS Verl E. McCoy, Chicago, 111., and Ralph W.Anderson, Wauwatosa, Wis.;l said McCoy assignor to Wilson EngineeringCorporation, Chicago, III... a corporation of Delaware Application June6, 1935, Serial No. 25.218

3 Claims.

This invention pertains to boiler feed apparatus for various types ofboilers, including locomotive boilers.

One of the advantages and objects of the invention is the provision ofmeans for assuring a high temperature to feed water being delivered athe water temperature to a temperature that might be uneconomicaltomaintain in the supply tank. a

' Other objects and advantages of the invention will become apparentfrom a perusal of the specification.

The drawings show a preferred form of the invention and a modified formthereof.

Fig. 1 is a side elevation showing a locomotive with one form of theinvention applied thereto;

Fig. 2 is an enlarged detail view in cross section of a mixer employedin that form of the invention;

Fig. 3 is a side elevation showing a locomotive with another form of theinvention applied thereto;

Fig. 4 is a sectional view on the line 4-4 of Fig. 3;

Fig. 5 is an enlarged detail view in section of a mixer employed in themodified form of the invention;

Fig. 6 is a partial sectional view on the line 6-6 of Fig. 5; and

Fig. 7 is a side elevation showing part. of a third form of theinvention.

Referring first to Figs. 1 and 2, pipe. 1 is connected with the sourceof feed water leading to the pump 2, the latter being driven by steamsupplied through the pipe 3. The pump delivers D the feed water into thepipe 4 through a check valve 5, interposed in the line to'preventreverse flow of the water and thence into Venturi-type mixer generallydesignated at 6. From the mixer, the water then passes through a boilerstop and check valve 1 into the water space in the boiler. The pump isintended to deliver water into the pipe 4 at a pressure higher than theboiler pressure, and irr any case will deliver the water into the boilerwhether or not heat is added to it in the mixer.

The mixer consists of a noz zleli, a chamber 9, and a Vjenturi tube l-l.I w

A pipe i2 is connected with the steam space of the boilerv fordelivering live steam preferably": at V or near the boiler pressure intothe chamb er oi the mixer. A valve -l-3will ordinarily be inter posed inthe pipe I2'so that thesteam may be shut ofi manually from this pipe.whenever desired, or a remotely eontrolled valvemay be em- I ployed ifdesired. Also, if desired, a check valve 14' may be positioned in thepipe l2 to'prevent the feed water from flowing into the steam space, butpermitting steam to' flow toward the mixer.

In the usual operation of the devicawhen the feed water pump starts, thewater delivered by the pump will have its static pressure temporarilydecreased as it passes through the chamber 9 between the nozzle and theV-enturi tube. mixer is so designed that this pressure will be loweredat least a few pounds below the pressure of the steam supplied by thepipe l2, hence this pressure difierential will entrain steam from thepipe 12 and mixing of the steam and waterv will occur in theVenturi'tube; V from the Venturi-tube its static pressure is' re storedto approximately its former pressure.

The feed water delivered by the pumpmay have a temperature ranginganywhere' f-rom atmospheric temperature up to approximately itsatmospheric boiling point, depending upon the amount of heat supplied toit previously in the supply tank or elsewhere. In any event, however,the admixture of the live steam with this water will raiseitstemperature greatly and will assure thedelivery of the feed waterinto the boiler at temperatures'which will not be-solow as to beharmful. The temperature increasethus obtained may range in practiceanywherefrom 50 to 150 F. ormore, up to the-boiler tempera ture.

Not only is thetemperature of theiwa-tierraised I vision is not'iece'ssary. The boiler-steam pres- V The I As the-water emerges sure maybe maintained at all times in the pipe l2 and thelive steam may thus beheld ready for use any time the feed pump starts. In this manner theautomatic mixing of live steam with the feed water will be assuredwithout requiring any complicated mechanism. Whenever the pump stops,the flow of steam through the pipe 2 also will stop, the check valve 5serving to prevent the escape of steam back toward the pump.

In the other form of the invention shown in Figs. 3 to 6, inclusive,provision is made for using exhaust steam whenever it is available andlive steam when the exhaust steam supply is lacking, for heating thewater immediately prior to its entry into the boiler.

A pipe 2| is connected with a source of feed Water, for example a tendertank, or a special feed water compartment, and leads to the pump 22, thelatter being driven by steam supplied through the pipe 23. This pumpdelivers the feed water into the pipe 24 through a check valve 25 whichis interposed in the line to prevent reverse flow of the water andthence into a Venturi type mixer, generally designated as 25. From themixer, the water then passes through a boiler stop and check valve. 21into the water space in the boiler. The pump is intended to deliverwater into the pipe 4 at a pressure higher than the boiler pressure.

The mixer consists of a chamber 28 into which a nozzle 29 projects. Aneedle valve 3i is employed to regulate the effective area of the nozzleand is secured to a piston 32 located in the cylinder 33. A pipe 34 isconnected with the steam space in the boiler and maintains boilerpressure constantly on the adjoining side of the piston. The pipe 24 isconnected with the inlet port 35 and delivers water into the chamber 33always at a pressure higher than the boiler pressure. In

order that the pump pressure, acting through the holes 31, may not drivethe piston to the left and open'the nozzle wide, a spring 38 is locatedas shown to partially offset the excess of water pressure. It will be ofsuch a strength that when the pump stops and the water pressure at theport 35 ceases, the needle valve will close, but will open when the pumpstarts. As the velocity of the pump is increased and the water pressurethereby increases, the needle valve will recede from the nozzle outlet.Thus by regulating the effective area of the nozzle aperture thepressure of the water delivered from the nozzle into the chamber 28 maybe held within close enough limits as to assure that the jet of waterprojected into the frustro-conical members 39 will produce a high vacuumin the chamber whereby exhaust steam at any available pressure may thusbe introduced through and between the cones into the water stream. Also,this method of regulating the nozzle orifice avoids placing an undueload on the pump when it is operating at full capacity.

Preferably the members 39 are formed integrally with the Venturi tube4!, with suitable spacing and apertures as shown, and the tube isconnected with the pipe 42 for delivering water into the boiler. Theexhaust steam which is drawn into the water stream will be condensedthereby and will, when an ample supply of the exhaust steam isavailable, impart enough heat to prevent the introduction of harmfullycool water into the boiler.

Should the supply of exhaust steam be insufficient for properly heatingthe water, or be entirely lacking, as may happen when the engine isdrifting, means are provided for introducing live steam to supplement orreplace the action of the exhaust steam. Accordingly, a pipe 43 isconnected to the steam space in the boiler and to the vacuum chamber inthe mixer and is provided with a thermostatically controlled valve 44Whose temperature sensitive element is disposed in the pipe 42. Hencewhen the feed water emerging from the Venturi tube is below apredetermined desired temperature, the valve 44 will become opened andlive steam will be introduced into the water in amount sufficient tocreate the water temperature desired.

The exhaust steam which is supplied to the mixer will ordinarily bepicked up from the exhaust of the cylinders, a pipe 45 being providedfor this purpose and being connected to the cylinder exhaust duct in anysuitable manner. The point of connection and the manner of connectionare not important. This pipe will preferably be installed, as shown,either on the exterior of the boiler shell, or it may be located insidethe front end. At its highest point a vacuum relief valve 46 of ordinaryand suitable construction will be installed to admit air to this pipe,should a partial vacuum therein occur. The mixer is connected by a shortpipe 47 to the pipe 45.

It is contemplated that when the pump is starting some water will bespilled by the mixer until the velocity of the water jet is sufficientto cause all of the water to bridge the gap and enter the Venturi tube.This spilled water will be allowed to flow into the pipe 48 and will beconducted rearwardly through the check valve 49 preferably back into thefeed water supply tank, tender tank or other storage space for feedwater, but might be allowed to spill on the ground. Because of theposition of the connection of pipes 41 and 45, none of the spilled watermay go over into the pipe 45 and enter the engine cylinders. Also thetop or the loop in the pipe 45 is high enought so that, when thelocomotive is on the steepest downgrade that may be encountered and whenthe forward end of the locomotive is downhill any water which might flowforwardly through the pipe 48 and leak past the check valve 49 cannotenter the engine cylinders.

The second described form of the invention has the particular advantageof using exhaust steam, a waste product, for raising the temperature ofthe feed water. When the mixer is properly designed the feed water fromthe tender tank can be raised in temperature from 32 F. to thesaturation temperature of the exhaust steam available for heating.

In the operation of the apparatus shown in Figs. 3 to 6, inclusive,whenever the feed pump is started by opening the steam supply valvelocated in the cab, the water delivered through the pipe 24 will, in ashort time, producev a vacuum in the chamber 28 and draw in exhauststeam and cause it to be mixed in the Venturi tube with the feed water,if exhaust steam is available. Otherwise, in the absence of exhauststeam or due to an insufiicient supply of exhaust steam, the delivery ofwater into the pipe 42 at a temperature below some predeterminedtemperature will cause the valve 44 to open up and admit live steamdirectly from the boiler into the mixer. Hence at all times theapparatus insures that feed water delivered into the boiler will nothave a harmfully low temperature. The capacity of the mixer and thesupply of steam will be such that enough steam can always be added tosufficiently increase the feed water temperature for the protectivepurposes desired;

Fig. '7 illustrates a third embodiment of the invention. In this form ofthe invention the mixer shown in Fig. 5 is employed with the exceptionthat the live steam supply pipe 43 is omitted. This modified mixer isgenerally indicated as 26 in Fig. '7. The apparatus shown in this figureis intended to replace the apparatus shown in the similar area of Fig.3, the pipe 24 being connected to the pipe 24, the pipe 48 beingconnected to pipe 48, 45' to 45, the relief valve 46 being identicalwith and a substitute for the relief valve 46. In this modification,live steam from the boiler, acting through the pipe 34' regulates theneedle valve, while the water is supplied to the mixer from the pipe 24,while the exhaust steam is supplied by the pipe 41'. The Venturi tube 4|is connected to the pipe 42' and delivers the water through a checkvalve 59, thence into the entering end of another Venturitype mixerwhich is identical in design with the mixer shown in Fig. 2. This mixeris designated 6' and has a Venturi tube H which delivers the waterthrough the stop and check valve 21' into the boiler.

I3 supplies live steam from the steam space in the boiler to this secondmixer. This modified form, therefore, consists substantially of themixers shown in Figs. 2 and 5 arranged in series, omitting the livesteam supply to the exhaust steam mixer and supplying the live steamonly into the second mixer. With this arrangement, feed water having atemperature even as low as 32 F. may receive a boost in temperature upto the saturation temperature of whatever exhaust steam is available forheating. Whether or not this water is then sufiiciently heated, it will,in its passage through the second mixer, have its static pressuresufi'iciently lowered so that live steam from the boiler may be mixedthereinto, as will be understood from the previous description of Fig.2. In the second mixer the water may receive a further boost intemperature which may range up as high as a 150 F. increase, dependingupon the proportioning of the parts. Thus when a high pressure boiler isbeing fed with the apparatus now being described, the feed watertemperature may be raised as high as 300 F. and higher, a part of theheat being recovered from the exhaust steam and additional heat beingsupplied by live steam to make certain that feed water cannot enter theboiler at such a low temperature as to do damage therein.

Referring now to Fig. 3, the pump 22 when running is always delivering aconsiderable amount of exhaust steam, hence arrangements are herein madeto condense that steam by connecting the pipe 5!, as shown, to a jetcondenser 52 and causing the exhaust steam to inject water from the pipe5| into the return pipe 48. Thus the heat of this exhaust steam issaved.

While the invention is illustrated as being applied to a locomotive, itis obviously capable of being used with other boilers, includingstationary boilers of various kinds. Furthermore, the drawings andspecification illustrate and describe merely a few embodiments of theinvention. Va-

A pipe l2 controlled by the valve' riations and other modifications ofthe invention are contemplated and may be employed without any departurefrom the spirit and scope of the means including a pump for withdrawingfeed I 7 water from a supply source and delivering it at a pressureexceeding the existing boiler pressure, means for temporarily increasingthe water velocity and decreasing the static water pressure to a rangebelow the pressure of exhaust steam from the locomotive cylinders, meanscontrolled by the delivery pressure-of said pump for regulating saidwater pressure and velocity, means for introducing cylinder exhauststeam into said water while at said lowered pressure, and means fordecreasing the velocity of the water and raising its pressure after saidintroduction of exhaust steamto an excess over the boiler pressure anddelivering the same into the boiler.

2. In combination with a locomotive boiler, means including a pump forwithdrawing feed water from a supply source and delivering it at apressure exceeding the existing boiler pressure, means for temporarilyincreasing the water velocity and decreasing the static water pressureto a range below the pressure of exhaust steam from the locomotivecylinders, said means including a nozzle and a valve for regulating theeffective area of the nozzle, means controlled by the delivery pressureof said pump foroperating said valve to regulate the flow of waterthrough said nozzle for controlling said static water pres sure, meansfor introducingcy linder exhaust steaminto said water while at saidlowered pressure and means for decreasing the velocity of the water andraising itspressure after said introduction of exhaust steam to anexcess'over the boiler'pressure and delivering the same into the boiler.

3. In combination with'a boiler, means including a pump for deliveringfeed water' at a pres sure exceeding the boiler pressure, a mixer including a chamber, a combining tube and a jet for projecting the waterdelivered by the pump through the chamber into the tube, means forintroducing cylinder exhaust steam into said in the jet, a cylinderhaving a piston therein rigidly connected with said valve, the side ofthe piston toward said valve being exposed to the delivery pressure ofthe pump, a pipe communieating from the steam space in the boiler to theopposite end of said cylinder to subject said piston to the boilerpressure, a pipe connected for delivering water from the pump to theintake end of said jet, and a pipe connected with the combining tube fordelivering a mixture of water and steam into the boiler, said pistonserving to operate said valve to increase the effective area of the jetas the pump delivery pressure increases and decrease said area as saidpump pres sure decreases. V

' VERL' E. MCCOY.

RALPH W. ANDERSON.

' chamber, a needle valve for regulating the orifice

